Students read descriptions of the voltage, current, and turns ratios of the primary and secondary coils for a transformer in this interactive lesson.

In this animated activity, learners see that changing the resistance value of the load in the secondary of a transformer causes current to vary in the primary.

Learners read an analogy comparing an electrical transformer to mechanical gears.

Students solve practice problems on voltage, current, and impedance matching. Examples precede the problems.

Students read an introduction to transformers that includes schematic symbols, turns ratios, mutual inductance, and the coefficient of coupling.

Learners view animations and video clips showing how power is transmitted from one energized coil to another.

Students follow the steps that are required to select a transformer with the proper ratings. Voltage, frequency, current, and KVA are considered.

In this animated object, learners study the operation of a linear voltage differential transformer. A brief quiz completes the activity.

Learners examine how the load resistance connected to the secondary coil of a transformer affects the primary current. A brief quiz completes the activity.

In this interactive object, learners follow steps to find phase voltages in a partial three-phase power distribution circuit.

Learners study how a circuit converts the AC output of a linear voltage differential transformer (LVDT) into variable DC voltage. It is recommended that learners view the learning object IAU7807, “The LVDT: A Linear Voltage Differential Transformer in Action” before going through this object.

Learners view the waveforms and voltages of an Edison Three-Wire System and read a description of the polarities across the secondary of the center-tap transformer. This transformer supplies power to residential homes.

Learners read a description of the wiring configuration of a residential Edison Wire System, which consists of a transformer secondary circuit. The circuit supplies two 115-volt sources and one 230-volt source.

Learners examine the impedance matching capability of a transformer and how to select the proper turns ratio to achieve this function. A brief quiz completes the activity.

Learners consider why an impedance matching transformer is needed to connect an antenna to a television.

Learners read an explanation of how the Magnetron Ignition System uses a solid state switching component, a step-up transformer, and magnetism to provide a high voltage spark in a one-cylinder combustion engine.

Using a memory shortcut for calculations, the learner determines line and phase values of current in a three-phase AC configuration. Practice problems complete the activity.

Learners follow a step-by-step explanation of how to test fuses and circuit interrupting devices.

Learners examine an electric motor control circuit that uses a motor starter module. This activity has audio content.

The learner will understand the operation of motor control circuits used to start and stop three-phase motors.